220 KEPOKT OF COMMISSlUNEFv OF tISH AND FISHKKIES. 



but. when they are vei-y leiin, as was the case in ISOG, lor instance, 

 from oG to 6G are required for 1 gallon of oil. In that fishery the liv- 

 ers are fatter at the beginning than at the end of the season. They 

 average about 55 i)ounds to the 100 fish; but during the years when 

 they are unusually lean it is much less, as in 1883, when the average 

 weight of 100 livers was onh' 12^ pounds. Usually at tlie Lofoden 

 Islands 250 to 1,100 cod give 1 barrel of livers, and 2 barrels of livers 

 yield 1 barrel of oil; but in 1883 from 700 to 1,100 fish were required 

 foi- 1 barrel of livers, and 4 or 5 barrels of those were necessary for 1 

 barrel of oil. Aside from the benefits accruing from the fatness of 

 the livers, anything gained in quantity is alwaj's lost in ([uality in the 

 preparation of medicinal oil. 



While it is somewhat difficult to distinguish among the oils made 

 from the livers of the various members of the cod famity, yet ordina- 

 rily there are certain distinctive characteristics apparent to the skilled 

 oil-refiner. Cod oil is of a greenish yellow color and usually has less 

 pressings or foots than any of the others. Hake oil is almost white, 

 but that made from hake taken on certain grounds has a X)inkish 

 color, which may be removed Iw filtration tlirough a mineral earth. 

 Pollock oil is distinguished by a slightlj^ bitter taste and has a faint 

 reddish cast. Its weather-test is rather lower than that of cod oil, 

 especially when it has been slightly overcooked in the rendering. 



Oil extracted from perfectly fresh cod livers is light and odorless, 

 and, owing to its extensive use in medicine, is known as medicinal cod 

 oil or "cod-liver oil." According to the extent of decomposition of the 

 material before the extraction of the oil, the color ranges through all 

 shades of yellow and brown to very dark brown, this color being 

 attributed to the decomposition of the hepatic tissues and fluids. 

 Tliese dai'k oils are of two general grades; one, the brown, which is 

 inferior to tlie light-brown or medicinal oil, but is frequently used for 

 such; and the other, the dark- brown or curriers' oil, is tlie poorest 

 grade pi-epared, and is exclusively used for technical i)urposes. Prob- 

 ably it would be bet tei- to say that there are two principal varieties of 

 oil, tlie medi(Mnal and the curriers', and that unusual nuirket condi- 

 tions may result sometimes in the emplojnnent of the poorest of the 

 medi('inal oil for technical uses or the best of the curriers' oil for 

 officinal purposes. 



The medicinal value of cod-liver oil was known centuries ago among 

 the Laplanders in noi'ther-n Europe, the descendants of the Norsemen 

 in Iceland, and the Eskimos in Alaska. The use of the oil gradually 

 extended in Euroj^e during the eighteen1,li centuiy, being a popular 

 home remed)' among many seacoast communities and used empiri- 

 cally by phj-sicians. Porcival and Bardsley in 1782 recommended its 

 use in cases of gout and chronic rheumatism. In 1841, J. Hughes 

 Bennett, of Edinburgh, publislied a pamphlet on its medicinal quali- 

 ties, strongly recommending it in many cases, and this had much to 



